1. Field of the Invention
Exemplary embodiments relate to an organic light emitting device and a method of fabricating the same.
2. Discussion of the Related Art
The importance of flat panel displays has recently increased with the growth of multimedia. Various types of flat panel displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), organic light emitting devices have been put to practical use.
The organic light emitting device has rapid response time, low power consumption, and self-emission structure. Furthermore, the organic light emitting device has a wide viewing angle, so that it can excellently display a moving picture regardless of the size of the organic light emitting device. The organic light emitting device can be fabricated in low temperature environment using a simple fabrication process based on the existing semiconductor fabrication process. Hence, the organic light emitting device is attractive as a next generation display device.
Further, the organic light emitting device may be classified into a bottom emissive type device, a top emissive type device, and a dual emissive type device based on a traveling direction of light. The organic light emitting display device may be classified into a passive matrix type device and an active matrix type device based on a driving method.
A fabrication method of the organic light emitting device generally includes a patterning process of an anode electrode, a formation process of an insulating layer, a deposition process of an organic material and a cathode electrode, a formation process of a passivation layer, and an encapsulation process.
FIG. 1 schematically illustrates a process for aligning a substrate with a shadow mask in a related art organic light emitting device.
As illustrated in FIG. 1, an organic material is deposited on a substrate 140 using a shadow mask 130 inside a vacuum chamber 110. In the deposition of the organic material, a tolerance between the substrate 140 and the shadow mask 130 may be 50 11 m. This leads to the accurate deposition on the substrate 140.
The substrate 140 and the shadow mask 130 can be aligned by accurately fitting an alignment key (not shown) formed on the substrate 140 with an alignment key 131 formed on the shadow mask 130 using a window 150 of a deposition device and a camera 160 installed outside the deposition device.
Because the substrate 140 used to fabricate the organic light emitting device is generally a transparent glass substrate, the alignment key (not shown) formed on the substrate 140 and the alignment key 131 formed on the shadow mask 130 are aligned on an opposite surface to the surface of the substrate 140, on which the organic material is deposited, using the camera 160.
In other words, because the organic light emitting device has the transparent glass substrate 140, the substrate 140 and the shadow mask 130 are aligned on an opposite surface to the surface of the substrate 140, on which the organic material is deposited, using the camera 160.
However, a flexible display device employing flexible properties of a metal includes an opaque substrate. Therefore, an alignment key formed on the opaque substrate of the flexible display device cannot be seen using a camera.
Accordingly, it is difficult to see the alignment key formed on the opaque substrate in an alignment process of the flexible display device including the opaque substrate.